The sediment in Shanzi deep reservoir in Fujian Province contributes phosphorus to the water, affecting its nutrient levels. By studying the sediment's phosphorus forms and the reservoir's conditions, researchers found that the sediment releases phosphorus into the water, especially in Autumn and Winter. This phosphorus release can make up 0.7% to 6% of the water's phosphorus levels, with the potential to impact the reservoir's overall health if external sources of phosphorus are reduced.